Interesting questions, but I would think that the answers given would be biased towards what people have.
I can' really answer the first question as it is a subgroup of the second question
but in honesty, the answer to the second question would have to be what most bashers have, as they make up the majority. So Traxxas would be a good guess, however you can't count out e-flight with the cx, cx2, bcp, bcpp, and the 400 now, not to mention whatever else they make. Or was this question related to only surface rc? See what I mean, even when trying to answer honestly the question is too ambiguous.
But those questions in general are related to a basher. Seeing as how you are posting the question on the onroad forum, where most of us race at least at the club level, your answer can be found by going through the first couple of pages of this forum. But all in all the answers will be biased towards what we drive.